Pen



FIG. 1 is a perspective view of the pen of the present invention;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left-side view thereof;

FIG. 5 is a right-side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The numerals and gradation marks occurring on the grip of the claimed design illustrate environment and form no part of the claimed design. 

The ornamental design for a pen, as shown and described. 